Milling tool



Jmzaze,1946.y R. GOTTUEB ,2,393,463-

' MIILLING TooL y Filed April 8, 1943 3 Sheets-Sheet l Jan. 22, 1946.

MILLING TOOL Filed Apri-i Yes, 1945 3 S'heets-Shee'( 3 III R. GQTTLIEB l 2,393,463

Patented Jan. 22, 1946 i e- UNITED STATES PATENT formes i Robert Gottlieb, Newport News, ve., assigner-of e one-half to Albert Sherman, Bronx, N.

ApplicationrApril 8, 1943, Serial No.7'482,304

6 Claims `(Cl. .Wl-412) The present invention relates to milling cutters andparticularly to milling cuttersjof light Weight and small vsize and which are primarily intended for use Vas hand tools. v

While many types of milling cutters have heretofore been designed or suggested but fewhave been intended for hand manipulation and, of those which have been designed'in such man-V ner that they may be readily maneuvered in the hands of an operator so as to be applied to a piece of work Vin various Ways, no such cutter heretofore'designed or used has been/found to be lcapable of use in removing projections from articles having relatively Smooth surfaces, for instance the heads of rivets which project above or beyond the surfaces of sheet metal member through which the rivets extend. In thefmanufacture of certain types of airplane wings and bodies for instance it is now found to be desirable to remove any small projecting rivet heads after. the completion of all of ,the customary rivetingr operations. l

It is-.a lpurpose of the present invention to provide a milling cutter which, while of general utility, is particularly suitable for use inthe removal'of thosev portions of rivet heads which project,- fromhsmooth surfaced bodies. It Will be appreciatedthat such a device, to be effective, must precisely remove the rivet head, but must not impair the smooth surface of the sheet or body through which the rivet passes.- Any hand manipulated tool, such as a milling cutter, and which is power driven, must therefore beprovided with means to govern and control the cutting action of the milling cutter` most precisely.L In accordance with the present invention a safeguarding and out clearance-controlling means of novel character is provided, rendering the use of such tool eminentlypractical, it being quite possible with the aid of the improved milling cutter for an operator who lacks mechanical skill or long training to successively accomplish rapidly and economically the precisefrivet head removing operation. l

In the acompanying drawings ltwo embodiments of the improved milling tool are disclosed by way of example. It will be appreciated by those skilled in the art that, in adapting the in- Figure 1 is a rear elevation of one form ofthe millingotoolembodying the invention; Figure 2 is'a side elevation of the tool, its central portion'being broken away, however, to

show the interior details of construction;

Figure 3 is an end View of the tool, showing it inr position lto remove the heads from a row of rivets which have been passed through two members to be secured together;

Figure 4 is a section on line -fl of Figure 2;A

VFigure 5 is a section on line 5-5 cf-Figure 2;

Figure 6 is asection on line 5-6 of Figure 1;

Figure '7 is an edge View of the milling cutter;

Figure 8 is a view, partially in sectionand partially in elevation, ofA an alternative form of cutter;

Figure 9 is a top plan view of thecutter shown in Figure 8r also partially -cut away to show in*- terior parts; j

Figure 10 is a section on line yI i-I B or Figure 8 on a somewhat larger scale; h

Figure 1l is a section on line II-iI of Figure 10; and y Figure 12 is a section on line I2-I2 of Figure vention for the accomplishment of specic objectives, the design and arrangement of thecomponent elements of the cutter may be considerably modied. Those forms, therefore, of the cutter which are disclosed are set forth by way of example.

In the drawings:

In the form of the `invention disclosed in Figures` l to '7, inclusive,` the milling cutter is indicated at IILr this cutter comprising a relatively short cylindrical body vand a plurality of peripheral blades Illa. Encircling the periphery of lthe cutter is the cylindrical midportion II of a three-partvhousing, the housing end portions beingr indicated at I2 and I3, respectively. To the housing' end' portion VI2 is secured, as by means of v.screw bolts I4, a cylindrical handle I5 and to the housing I3 there is secured a cylindrical motor housing I5, the reduced inner end of `this housing having threaded engagement with the inner wall of a recess formed in the tubular portion I3a of housing member I3. Motor housing i5 is cylindrical and likewise functions as a handle, its axis being aligned with the axis of handle,y I5 and 'the milling cutter I being coaxial withthe handles so that theoperator, by grasping the members I5 and I, can present the cutting blades of the milling cutter to any specified. piece of work, and can also exert the desired pressure to force the cutting blades against the work. In order thatY the cutting blades shall not at any time be caused or allowed to engage the surface from which the rivet heads project rolling'guides are provided, these guides beingindicated at IBl and I9 in the drawings. lt will be observed that the outside cylindrical surfaces of the guides, which are of similar nature and annular in form, are substantially equal in diameter to the diameter of the circle which passes through the outer peripheries of the cutting edges of the teeth. The guides are so mounted, however, that they may be independently adjusted in planes normal .to the axis of the milling cutter, i. e., radially of the milling cutter, so that the cylindrical outer surfaces thereof which contact with the work may be precisely positioned to give the milling cutter the exact depth of cut desired.

The milling cutter itself is fixed upon the cutter shaft 20, the cutter shaft being mounted in anti-friction bearings, preferably ball bearings 2I which bearings are in turn supported upon cylindrical hubs I2a and I3b which form portions of the casing and parts I2 and I3 respectively. The rolling guides I8 and I9 are carried, respectively, by annular carriers 22 and 23, respectively, these carriers encircling the hubs I2a and I3b and being substantially coaxial therewith, the cylindrical inner surfaces of the carriers, however, being spaced from the cylindrical outer surfaces of the hubs in order that the carriers may be adjusted relatively to the hubs in planes normal to the cutter axis.

The means for adjustably supporting the carrier 22 upon the hub I2a comprises aligned diametrically opposed screws, these screws being indicated at 24 and 25, respectively, each having threaded relation with a cylindrical inner wall of the radial recess in the associated carrier through which it passes and each having its pointed inner end in engagement with the hub I2a. It will ,be

l observed that inserts in the nature of bushings 26,

supported in recesses formed in the hub I2a, are provided with conical seating surfaces to receive with a close fit the conical inner ends of the supporting screws 24 and 25, respectively. When these supporting screws are firmly seated as shown in Figure 2 the carrier 22 will be maintained in the position in which it is shown and, when the tool is in use the common axis of the adjusting screws 24 and 25 will be substantially vertical so that the screw 24 may be designated the upper screw and the screw 25 the lower screw. The outer end of each screw may be reached with a screwdriver, an aperture IIa being formed in the cylindrical casing I I for the passage of a screwdriver to each screw 24, and the outer end of the lower screw 25 being at all times visible and accessible.

The means for adjustably supporting the carrier 23 upon the hub ISb, and hence adjusting rolling guide I8 radially of the cutting axis, is identical with that just described for adjustably supporting the rolling guide I9. guides I8 and IS are, of course, individually adjustable and such adjustment may be effected from time to time as may prove to :be necessary to give the desired depth of cut, the guides being adjusted upwardly from time to time as the cutting blades wear. The tool functions as a precision instrument, the cylindrical surfaces of the rolling guides I S and I9 being closely adjacent the milling cutter IIJ so that pressure upon the operating handles cannot disturb the relationship between the guiding surfaces and the cutting edges of the milling cutter. The screws 24 and 25 in reality comprise adjustable supports for the rolling guides and are so positioned, as previously pointed out, that when a tool is in cutting position, as shown in Figures 2, 3 and 4, adjustment of the screws effects vertical adjustment of the rolling guides. By reason of the use of ball bear- The rolling ings as anti-friction means between the rolling guides I9 and the annular carriers 22, the cutter shaft 20 and the hubs I2a and I3b, friction is reduced to the minimum and high speed operation made possible.

Suitable spacers indicated at 30, encircling the cutter shaft 20 and annular plates 3|, secured t0 the ends of the respective hubs I2a and |312, serve to retain the annular roller guide supporting bearings 32 in position. A suitable nut 34, which may be an elastic stop nut, has threaded relation with one end of the milling cutter shaft 20, and bears against an annular washer 35 which confines the inner race of the inner ball bearing 2I. The enlarged opposite end of the milling cutter shaft 20 is operatively connected by means of an axially extending coupling member 36 with the rotor of an air motor enclosed within the housing I6. This air motor is not shown in detail and need not be described in detail inasmuch as any suitable motor, of which there are a number available on the market, may be employed to rotate the cutter shaft through the intermediate coupling member 36. It may be said, however, that a flexible conduit 4I! from a suitable source of air under pressure may conveniently be connected to the coupling 4I attached centrally to the outer surface of the cylindrical casing member II, air under pressure being led from coupling 4I through connecting duct 42 to the outer end of the motor housing I6. Conveniently also the exhaust air from the motor may be conducted through an exhaust duct 43 to a nozzle 44 which is directedv toward the teeth of the milling cutter, the air blast issuing from nozzle 44 striking each successive tooth just after it has completed its yworking stroke, the air jet serving to blow away any chips which may tend to cling to the tooth and also having a cooling effect.

In the form of the invention shown in Figures 8 to 12, inclusive, the cutter 55 is mounted upon cutter shaft 5I by anti-friction means comprising roller bearings 52 and 53, so that the cutter may freely revolve on the cutter shaft instead of revolving with the cutter shaft as in the rst form of the invention. The housing comprises two parts 54 and 55 secured together by bolts 56 and includes aligned hubs 54a and 55a in which the ends of the cutter shaft 5I are fixed. Encircling the hubs 54a and 55a are annular carriers 58 and 59, respectively, the inner cylindrical surfaces of these carriers being spaced from the cylindrical outer surfaces of the hubs 54a and 55a, as shown, to permit radial adjustment of the carriers with respect to the hubs and the cutter shaft. Rotatably supported upon the carriers 58 and 59 are the rolling guides 60 and 6I respectively, the cylindrical outer surfaces of these guides being adapted to engage the surface of a sheet metal member such as that indicated at 62 in Figures 8 and 10, to properly position the teeth of the cutter 5I] so that the cutter can remove the projecting head of a rivet B3 Without cutting into the surfaces of the plate 62.

The means for supporting the carriers 58 and 59 in the casing comprise adjusting screws as before, including upper adjusting screws 64 and 65 and lower adjusting screws E6 and 61. By loosening the lower screws 65 and 61 and tightening the upper screws 54 and V65, the rolling guides 60 and 6I may be lowered with respect to the cutter 50 and the cutting clearance increased. By reversing this process the cutting clearance may be decreased.

The blades 50a of the cutter 50 not only comprise cutting instrumentalities, but likewise comprise vanes against which jets of motive fluid under pressure are directed to cause rotation of the cutter. It win be observed in Figure s 'of the drawings that the housing includes an arc-shaped duct or passage which is in constant communication with duct 1l which extends axially through the handle 12 which is attached to the casing or housing. In the inner wall of duct 'l0 are formed one or more short passages 13 which serve to direct jets of air or other motive iluid against the rear faces of the several cutting teeth 50a of the cutter, the rear surfaces of these teeth being cylindrically formed as shown in order to utilize to the maximum extent the kinetic energy of the several streams of motive fluid. By using air under substantial pressure the cutter 50 may be revolved at high speed. The duct passing through handle 12 is controlled by a ball valve 14 normally pressed` by a spring 15 against a seat 16.` A rotatable cylindrical plug 11, retained within a radial cylindrical aperture in the wall of the handle 12, carries at one end an eccentric pin V18 and at the other end, which is the outer end, a knurled button or linger-piece 8|). By rotating the plug 11 the eccentric pin may be caused to lift the ball 14 from the seat-16 and to thus hold the valve open permitting flow of compressed air to the tool. When the plug 11 is turned to the position in which it is shown in Figure 9, however, ball 14 will seat and the flow of air thus be interrupted.

This form of milling cutter may be operated with great convenience in restricted spaces, only one hand of the operator being necessary to manipulate it and control it. It isof simple and rugged construction, inexpensive to construct and operate and of wide utility.

Having thus described the invention, what is claimed as new and desired to be secured by Letters Patent is:

1. A milling tool for use in removing those portions of rivets or the like which project outwardly beyond the smooth surfaces of riveted articles, comprising a housing having spaced coaxial hubs, a milling cutter shaft coaxial with said hubs and rotatably supported thereby, a milling cutter fixed on said shaft intermediate said hubs, an annular guide on each side of said milling cutter, an annular carrier associated with each annular guide and upon which such' guide is rotatably supported, and means supporting said carriers, respectively, upon said hubs, for adjustment radially of the milling cutter shaft.

2. A milling tool for use in removing those portions of rivets or the like which project outwardly 55. V

beyond the smooth surfaces vof riveted articles, comprising a housing having spaced coaxial hubs,

a milling cutter shaft coaxial with said hubs and Y rotatably supported thereby, a milling cutter fixed on said shaft intermediate said hubs, an annular guide on each side of said milling cutter, an annular carrier associated with each annular guide and upon which such guide is rotatably supported, and means supporting said carriers, respectively, upon said hubs, for adjustment individually radially of the milling cutter shaft.

3. A milling tool for use in removing those portions of rivets or the like which project outwardly beyond ythe smooth surfaces of riveted articles, comprising a housing having spaced coaxial hubs, a milling cutter shaft coaxial with said hubs and rotatably supported thereby, a milling cutter fixed on said shaft intermediate said hubs, an annular guide on each side of said milling cutter, an annular carrier associated with each annular guide and upon which such guide is rotatably supported, each such carrier vencircling one of said hubs, and means for adjustably supporting each carrier upon the associated hub for adjustyment radially thereof, said means including screws passing radially through the carrier and engaging the hub.

4. A milling tool for use in removing those portions of vrivets or the likewhich project outwardly 'beyond the smooth surfaces of riveted articles,

comprising a housing having spaced coaxial hubs, aV milling cutter shaft coaxial with said hubs and rotatably supported thereby, a milling cutter fixed on said shaft intermediate said hubs, an annular guide on each side of said milling cutter,

'an annular carrier associated with each annular guide and upon which such guide is rotatably supported,Y each such carrier encircling one of said hubs, and means for adjustably supporting each carrier upon the associated hub for adjustment radially thereof, said means including aligned radially disposed adjusting screws the body portion of each has threaded engagement with said carrier and the inner end of which engages the hub.

5. The combination vset forth in claim 4 in which the said hubs are provided with hardened steel inserts to receive the inner ends of the adjusting screws.

6. The combination set forth in claim 4 in which said screws are so positioned that, when the tool is positioned for cutting, the aligned axes of the pairs of adjusting screws are substantially vertically disposed.

ROBERT GOTTLIEB.' 

